nest egg vs pork barrel

nest egg

noun
  • A saving; a reserve of money. 

  • A natural or artificial egg placed in a bird's nest, to encourage the bird to lay its own eggs there. 

  • An egg squash. 

pork barrel

noun
  • A ready supply of income; one's livelihood. 

  • State funds as assigned for local or regional expenditure; especially, central money used for regional projects which are eyecatching or designed to appeal to voters. 

How often have the words nest egg and pork barrel occurred in a corpus of books? (source: Google Ngram Viewer )